Interpretation of volatile - two questions

[Doug Gwyn]

In article <2604A628.8521 at paris.ics.uci.edu> rfg at paris.ics.uci.edu (Ronald Guilmette) writes:
>does the standard (a) permit, (b) require, or (c) prohibit the assignment
>statement shown to access the c2 field of the "struct s" pointed to by
>memory_mapped_device_p?

It requires that the implementation document its rules for access to
volatile objects, which presumably should include cases of access to
such an object as a side effect of accessing a non-volatile one, as
in your example.  Obviously choice (b) would have been silly and
choice (c) would be an impossible constraint on some architectures.